Posts tagged genetics

First comes the unscratchable itching, and the angry blossoming of hives. Then stomach cramping, and—for the unluckiest few—difficulty breathing, passing out, and even death. In the last decade and a half, thousands of previously protein-loving Americans have developed a dangerous allergy to meat. And they all have one thing in common: the lone star tick. Red meat, you might be surprised to know, isn’t totally sugar-free. It contains a few protein-linked saccharides, including one called galactose-alpha-1,3-galactose, or alpha-gal, for short. More and more people are learning this the hard way, when they suddenly develop a life-threatening allergy to that pesky sugar molecule after a tick bite. Yep, one bite from the lone star tick—which gets its name from the Texas-shaped splash of white on its back—is enough to reprogram your immune system to forever reject even the smallest nibble of perfectly crisped bacon. For years, physicians and researchers only reported the allergy in places the lone star tick calls home, namely the southeastern United States. But recently it’s started to spread. The newest hot spots? Duluth, Minnesota, Hanover, New Hampshire, and the eastern tip of Long Island, where at least 100 cases have been reported in the last year. Scientists are racing to trace its spread, to understand if the lone star tick is expanding into new territories, or if other species of ticks are now causing the allergy.

After spending so much time researching CRISPR, I thought I’d save everyone else the time, write a summary of why I think it’s a big deal, and then curate some of the best content on the subject I found.

The baby is not the first child to be born with DNA from three people. In the 1990s, fertility doctors tried to boost the quality of women’s eggs by injecting cytoplasm, the cellular material that contains mitochondria, from healthy donor eggs. The procedure led to several babies being born with DNA from the parents plus the healthy donor. Some of the children developed genetic disorders and the procedure was banned. Speaking about the latest case, Dusko Ilic, a stem cell scientist at King’s College London, said: “Without much ado, it appears the first mitochondrial donation baby was born three months ago. This was an ice-breaker. The baby is reportedly healthy. Hopefully, this will tame the more zealous critics, accelerate the field, and we will witness soon the birth of the first mitochondrial donation baby in the UK.”

To investigate the molecular bases of cephalopod brain and body innovations, we sequenced the genome and multiple transcriptomes of the California two-spot octopus, Octopus bimaculoides. We found no evidence for hypothesized whole-genome duplications in the octopus lineage. The core developmental and neuronal gene repertoire of the octopus is broadly similar to that found across invertebrate bilaterians, except for massive expansions in two gene families previously thought to be uniquely enlarged in vertebrates: the protocadherins, which regulate neuronal development, and the C2H2 superfamily of zinc-finger transcription factors.

Curiosity does not seem to be a fundamental drive, unlike what I am told are the three basic biological drives (seeking pleasure, avoiding pain and conserving energy), so it is probably derived. Curiosity requires a certain energy surplus, since its visible signature is a restless dissipation of energy, but it does not seem directly motivated by energy conservation concerns. So is it derived from pleasure-seeking or pain-avoidance or some mix of the two? Does that make a difference?